Patents by Inventor Huy M. Nguyen
Huy M. Nguyen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20090278565Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.Type: ApplicationFiled: July 20, 2009Publication date: November 12, 2009Applicant: Rambus Inc.Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
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Patent number: 7564258Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.Type: GrantFiled: August 17, 2007Date of Patent: July 21, 2009Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
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Patent number: 7525338Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.Type: GrantFiled: December 13, 2006Date of Patent: April 28, 2009Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
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Publication number: 20090034344Abstract: A data system component having a state machine circuit and receivers that utilize high and low threshold signals permits accurate detection of strobe signal pattern edges such as those for preamble, burst and post-amble conditions in the strobe signal. The state machine circuit may then be configured to set conditions associated with further circuit elements such as for power saving, data reception, on-die termination, etc. based on the conditions detected in the strobe signal to improve data or memory system performance. The components may be implemented as part of memory controllers and/or memory such as a dynamic random access memory and used in memory read and write operations.Type: ApplicationFiled: July 24, 2008Publication date: February 5, 2009Applicant: Rambus, Inc.Inventors: Huy M. Nguyen, Vijay Gadde, Bret G. Stott
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Patent number: 7439789Abstract: Described are controllable termination impedances that may be adjusted collectively by a combination of digital and analog signals. Each adjustable impedance, responsive to the digital signals, establishes a gross termination resistance for one of a plurality of communication channels by enabling one or more of a plurality of parallel-coupled impedance legs. Each leg includes at least one transistor for controlling the impedance of the leg over a continuous range. An analog compensation voltage is level shifted and the resulting level-shifted signal is applied to the control terminals of the transistors of the selected impedance legs. The compensation voltage, and consequently the level-shifted signal, varies with supply-voltage and temperature fluctuations in a manner that causes the collective impedance of the selected legs for each channel to remain stable despite the fluctuations.Type: GrantFiled: March 7, 2007Date of Patent: October 21, 2008Assignee: Rambus Inc.Inventor: Huy M. Nguyen
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Publication number: 20080211536Abstract: Described are amplifiers that facilitate high-speed communication with calibrated drive strength and termination impedance. Drivers and termination elements can be divided into a number N of parallel portions, one or more of which can be disabled and updated without interfering with signal (e.g., clock or data) transmission. Some embodiments identify inactive elements by examining incoming signals.Type: ApplicationFiled: May 7, 2008Publication date: September 4, 2008Inventors: Huy M. Nguyen, Vijay Gadde, Sivakumar Doriaswamy
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Patent number: 7389194Abstract: Described are amplifiers that facilitate high-speed communication with calibrated drive strength and tennination impedance. Drivers and termination elements can be divided into a number N of parallel portions, one or more of which can be updated while signals (e.g, clock or data) are transmitted. Some embodiments identify elements in a high-impedance state by examining incoming signals.Type: GrantFiled: July 6, 2005Date of Patent: June 17, 2008Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Vijay Gadde, Sivakumar Doraiswamy
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Patent number: 7199605Abstract: An apparatus is described having a feedback loop. The feedback loop has an output that approaches a steady state as a data line voltage approaches a reference voltage. The apparatus also includes a driving transistor that drives the data line. The driving transistor has an output impedance that is controlled by the feedback loop output, the feedback loop output keeps the driving transistor output impedance within a high output impedance region when the feedback loop output reaches the steady state.Type: GrantFiled: June 1, 2005Date of Patent: April 3, 2007Assignee: Rambus Inc.Inventors: Leung Yu, Roxanne T. Vu, Benedict C. Lau, Huy M. Nguyen, James A. Gasbarro
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Patent number: 7196567Abstract: Described are controllable termination impedances that may be adjusted collectively by a combination of digital and analog signals. Each adjustable impedance, responsive to the digital signals, establishes a gross termination resistance for one of a plurality of communication channels by enabling one or more of a plurality of parallel-coupled impedance legs. Each leg includes at least one transistor for controlling the impedance of the leg over a continuous range. An analog compensation voltage is level shifted and the resulting level-shifted signal is applied to the control terminals of the transistors of the selected impedance legs. The compensation voltage, and consequently the level-shifted signal, varies with supply-voltage and temperature fluctuations in a manner that causes the collective impedance of the selected legs for each channel to remain stable despite the fluctuations.Type: GrantFiled: December 20, 2004Date of Patent: March 27, 2007Assignee: Rambus Inc.Inventor: Huy M. Nguyen
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Patent number: 7161400Abstract: A circuit and method for synchronized clocking of components such as registers. Registers are clocked by individual component clock signals having the same frequency but potentially different phases due to differing propagation delays. Separate component clock signals are received by registers are brought into phase by evaluating the phases of the component clock signals at the registers, and synchronizing the component clock signal of each register to that of the previous register in a sequence.Type: GrantFiled: October 13, 2004Date of Patent: January 9, 2007Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Benedict C. Lau, Leung Yu, Jade M. Kizer
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Patent number: 7151390Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.Type: GrantFiled: April 6, 2005Date of Patent: December 19, 2006Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
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Patent number: 7135903Abstract: A phase-jumping locked loop circuit. The locked loop circuit includes a plurality of differential amplifiers and a biasing circuit switchably coupled to each of the differential amplifiers. Each of the differential amplifiers has inputs to receive a respective pair of clock signals and outputs coupled to a common pair of output signal lines. The biasing circuit comprising a first plurality of biasing transistors coupled in parallel with one another and in series with a first set of the differential amplifiers, and a second plurality of biasing transistors coupled in parallel with one another and in series with a second set of the differential amplifiers.Type: GrantFiled: February 25, 2003Date of Patent: November 14, 2006Assignee: Rambus Inc.Inventors: Jade M. Kizer, Benedict C. Lau, Roxanne T. Vu, Huy M. Nguyen, Leung Yu, Adam Chuen-Huei Chou
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Patent number: 7099786Abstract: A receiving unit may implement voltage compensation using a parameters table, an analog calibration component, and/or a digital calibration component. In certain implementation(s), an integrated circuit may include a voltage driver that modifies a supplied compensated voltage based on a feedback signal. The feedback signal may be produced responsive to a distributed voltage version of the compensated voltage, to a received data signal, and to a comparison involving an expected data value. In other implementation(s), a parameters table may be initialized by storing calibration values in entries in association with respective multiple identifications of multiple external points.Type: GrantFiled: February 24, 2005Date of Patent: August 29, 2006Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Benedict C. Lau
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Patent number: 7046078Abstract: An integrated circuit has one or more components that operate with reference to a distributed reference voltage. A reference voltage driver produces a compensated reference voltage, and the compensated reference voltage is distributed to form the distributed reference voltage at the components. Due to factors such as trace resistance and gate leakage, the distributed reference voltage is degraded relative to the compensated reference voltage. The reference voltage driver is responsive to feedback derived from the distributed reference voltage to adjust the compensated reference voltage so that the distributed reference voltage is approximately equal to a nominal reference voltage.Type: GrantFiled: May 11, 2005Date of Patent: May 16, 2006Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Benedict C. Lau, Adam Chuen-Huei Chou, Roxanne T. Vu
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Patent number: 7015721Abstract: An improved, open-loop push-pull driver is described. Closed-loop feedback loop techniques for control of the push-pull driver are described. These techniques are particularly well adapted to control shoot-through current in a push-pull driver circuit.Type: GrantFiled: August 24, 2004Date of Patent: March 21, 2006Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Benedict Lau, Roxanne Vu
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Patent number: 7002367Abstract: An apparatus is described having a feedback loop. The feedback loop has an output that approaches a steady state as a data line voltage approaches a reference voltage. The apparatus also includes a driving transistor that drives the data line. The driving transistor has an output impedance that is controlled by the feedback loop output, the feedback loop output keeps the driving transistor output impedance within a high output impedance region when the feedback loop output reaches the steady state.Type: GrantFiled: January 21, 2003Date of Patent: February 21, 2006Assignee: Rambus, Inc.Inventors: Leung Yu, Roxanne T. Vu, Benedict C. Lau, Huy M. Nguyen, James A. Gasbarro
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Patent number: 6924660Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.Type: GrantFiled: September 8, 2003Date of Patent: August 2, 2005Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
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Patent number: 6897713Abstract: An integrated circuit has one or more components that operate with reference to a distributed reference voltage. A reference voltage driver produces a compensated reference voltage, and the compensated reference voltage is distributed to form the distributed reference voltage at the components. Due to factors such as trace resistance and gate leakage, the distributed reference voltage is degraded relative to the compensated reference voltage. The reference voltage driver is responsive to feedback derived from the distributed reference voltage to adjust the compensated reference voltage so that the distributed reference voltage is approximately equal to a nominal reference voltage.Type: GrantFiled: February 14, 2002Date of Patent: May 24, 2005Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Benedict C. Lau, Adam Chuen-Huei Chou, Roxanne T. Vu
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Patent number: 6876248Abstract: A receiving unit may implement voltage compensation using a parameters table, an analog calibration component, and/or a digital calibration component. In certain implementation(s), an integrated circuit may include a voltage driver that modifies a supplied compensated voltage based on a feedback signal. The feedback signal may be produced responsive to a distributed voltage version of the compensated voltage, to a received data signal, and to a comparison involving an expected data value. In other implementation(s), a parameters table may be initialized by storing calibration values in entries in association with respective multiple identifications of multiple external points.Type: GrantFiled: May 28, 2002Date of Patent: April 5, 2005Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Benedict C. Lau
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Patent number: 6861884Abstract: A circuit and method for synchronized clocking of components such as registers. Registers are clocked by individual component clock signals having the same frequency but potentially different phases due to differing propagation delays. Separate component clock signals are received by registers are brought into phase by evaluating the phases of the component clock signals at the registers, and synchronizing the component clock signal of each register to that of the previous register in a sequence.Type: GrantFiled: August 4, 2003Date of Patent: March 1, 2005Assignee: Rambus Inc.Inventors: Huy M. Nguyen, Benedict C. Lau, Leung Yu, Jade M. Kizer